Design, synthesis, and physicochemical study of a biomass-derived CO2 sorbent 2,5-furan-bis(iminoguanidine)

Abstract

Summary In this study, the concept of biomass-based direct air capture is proposed, and the aminoguanidine CO 2 chemical sorbent 2,5-furan-bis(iminoguanidine) (FuBIG) was designed, synthesized, and elucidated for the physicochemical properties in the process of CO 2 capture and release. Results showed that the aqueous solution of FuBIG could readily capture CO 2 from ambient air and provided an insoluble tetrahydrated carbonate salt FuBIGH 2 (CO 3 ) (H 2 O) 4 with a second order kinetics. Hydrogen binding modes of iminoguanidine cations with carbonate ions and water were identified by single-crystal X-ray diffraction analysis. Equilibrium constant (K) and the enthalpies (ΔH) for CO 2 absorption/release were obtained by thermodynamic and kinetic analysis (K 7 = 5.97 × 10 4 , ΔH 7 = −116.1 kJ/mol, ΔH 8 = 209.31 kJ/mol), and the CO 2 -release process was conformed to the geometrical phase-boundary model (1-(1-α) 1/3 = kt). It was found that the FuBIGH 2 (CO 3 ) (H 2 O) 4 can release CO 2 spontaneously in DMSO without heating. Zebrafish models revealed a favorable biocompatibility of FuBIG.